BirdAnalyst
BBS Route · Colorado · BCR 18

Two Buttes Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 71 species recorded across 35 survey years, still active.

71Species RecordedSpecies recordedDistinct species detected on standard-protocol BBS runs here across all years on record — a measure of survey breadth, not a complete checklist.Full methodology →
35Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1973–2025Span
6Observers

Bird Species Found on Colorado Two Buttes

Top 40 of 71 species by most recent count. Each links to its species trend.

Species recorded on the Two Buttes route.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →History
House SparrowPasseridae1992025-35%1975
Horned LarkAlaudidae1372025-75%1975
Western MeadowlarkIcteridae1192025-87%1975
Mourning DoveColumbidae882025-63%1975
Lark BuntingPasserellidae612025-66%1975
Red-winged BlackbirdIcteridae422025-78%1975
Barn SwallowHirundinidae212025+412%1975
DickcisselCardinalidae212025+360%1993
Western KingbirdTyrannidae182025-80%1975
Rock PigeonColumbidae172025-40%1975
Grasshopper SparrowPasserellidae162025-90%1975
Ring-necked PheasantPhasianidae152025-90%1975
Lark SparrowPasserellidae102025+117%1979
Cassin's SparrowPasserellidae102025-93%1975
Bullock's OrioleIcteridae102025+44%1979
Cliff SwallowHirundinidae102025+183%1993
Common GrackleIcteridae52025+15%1977
Upland SandpiperScolopacidae51984-72%1975
Great-tailed GrackleIcteridae52025-50%2004
Burrowing OwlStrigidae42025-44%1975
European StarlingSturnidae42025+11%1977
Brewer's BlackbirdIcteridae42013+0%2005
Long-billed CurlewScolopacidae31994-94%1975
KilldeerCharadriidae32025-74%1975
Bank SwallowHirundinidae31995+91%1984
Brown ThrasherMimidae32025+250%1992
Yellow-headed BlackbirdIcteridae32008+0%1985
Vesper SparrowPasserellidae32012+0%2008
Eurasian Collared-DoveColumbidae32025+11%2012
Swainson's HawkAccipitridae22025-60%1975
Northern HarrierAccipitridae22009+33%1978
Field SparrowPasserellidae21975n/an/a
Blue GrosbeakCardinalidae22025+50%1994
Brown-headed CowbirdIcteridae22025-56%1982
Red-headed WoodpeckerPicidae22025+100%1979
Mountain PloverCharadriidae22015-53%1985
Scaled QuailOdontophoridae22014+67%1985
Orchard OrioleIcteridae21985+0%1981
Great Horned OwlStrigidae22015+40%1992
Brewer's SparrowPasserellidae22011-25%2005

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. A route is a sample, not a census.